Fuel slosh occurs when a vehicle with a fully or partially filled fuel tank accelerates, decelerates or executes a sharp turn. In response, liquid waves develop and collide and splash on the tank surface causing vibrations to develop in the fuel tank. Specifically, whenever a travelling liquid wave approaches a tank surface, it collides with vertical walls (front or rear) of the fuel tank and then climbs up and collides with a ceiling (e.g., top wall) of the fuel tank. Such vibrations generate air borne and structure based noises that are audible to a vehicle driver and occupants. Slosh noise is particularly problematic for hybrid and start-stop vehicles since periods exist in the drive cycle where background engine noise is absent. Wave impacts with the ceiling of the fuel tank, in particular, may create increased noise.
Other attempts to address fuel slosh noise include systems with multi-piece, complex baffle systems or baffles that are vertically oriented. One example approach is shown by Vaishnav et al. in U.S. patent application no. 2016/0096428. Therein, a baffle is mounted vertically within a fuel tank and faces of the baffle are arranged vertically within the fuel tank (e.g., perpendicular to the ground on which the vehicle sits).
However, the inventors herein have recognized potential issues with such systems. As one example, vertical baffle systems may not sufficiently reduce fuel slosh noise in the fuel tank. Specifically, such vertical baffle systems may not sufficiently retard the vertical motion of the liquid adjacent to walls of the fuel tank, and thus may not sufficiently reduce a wave amplitude of the liquid. As a result, fuel slosh noise may still be audible to the vehicle driver and occupants. Additionally, multi-piece baffle systems with complex parts may be difficult and costly to manufacture, and may take up significant space within the fuel tank.
In one example, the issues described above may be addressed by a baffle system for a fuel tank, comprising: a horizontal section; a vertical section arranged perpendicular to the horizontal section and including a first end coupled to the horizontal section, the vertical section extending across a length of the horizontal section; and an attachment surface coupled to a second end of the vertical section and including a plurality of apertures adapted to couple the baffle system to a top surface of the fuel tank. The baffle system may be installed in a fuel tank of a vehicle, the fuel tank having the top surface and a bottom surface arranged opposite and vertically below the bottom surface relative to the ground on which the vehicle sits. The horizontal section of the baffle system may be positioned vertically above and spaced away from the bottom surface of the fuel tank. Thus, in some instances the horizontal section may be positioned above a liquid fill level (e.g., fluid level) of the fuel tank. The horizontal section of the baffle system may retard the vertical motion of the liquid (e.g., fuel) within the fuel tank that is adjacent to tank walls of the fuel tank, thereby suppressing a wave amplitude of the fuel slosh wave within the fuel tank. Under certain driving conditions and fill levels, the fuel slosh waves may rise above horizontal section. During these conditions, the vertical section of the baffle system may provide secondary fuel slosh mitigation. In this way, the baffle system including the vertical and horizontal section may reduce the impact of the fuel slosh wave with the top surface (e.g., ceiling) of the fuel tank. As a result, fuel slosh noise may be reduced.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.